The Experimental Study Of The Peri-implantitis In Teeth Of Dogs

ObjectiveCurrently,the research on peri-implantitis is confined to delayed implant. The studyabout peri-implantitis induced by immediate implant is limited.The objective of thestudy is to establish experiment peri-implantitis induced by immediate implant, thenthe experimental group received periodontal treatment.The result of experiment canprovide some help to clinic research on Immediate implants for periodontitis.Methods1. Immediate implantExtract mandibular second, three, four premolar of six adult beagle dogs with goodhealth,then place implants (diameter3.8mm*length10mm)immediately. Secondsurgery was performed after3months of implants healing, silk ligatures would beforced into a position directly apical to the gingival margin of implants in order toestablish experiment peri-implantitis.2. Divide into three groups Six plants in every dog randomly divided into three groups：Group A、Group Band Group C. As a control group, dental plaque of Group A are shifted regularly. GroupB (peri-implantitis group+no periodontal treatment) The silk ligatures would beforced into a position directly apical to the gingival margin of implants in order toestablish experiment periodontitis. Group C (peri-implantitis group+periodontaltreatment) establish experiment periodontitis as Group B, remove the silk ligatures inthe fifth week, perform periodontal treatment for four weeks, every week regularly.3. Clinical examinationClinical and radiographic recording were repeated at1,2,3,4,5,6,7and8weeksrespectively after the abutments had been connected. The clinical examination includedmodified plaque index (mPLI), modified sulcus bleeding index (mSBI), peri-implantpocket probing depth (PPD). Collect Peri-implant sulcular fluid and record quality of itby electronic scale. Dogs were sacrificed8weeks after the abutments had beenconnected. Take bone block contained implants, make about20um slices,then picricacid-magenta stained. Compare gross examination, histological observation of threegroups.Results1. Differences in clinical indicatorsAs time moving, after8weeks, Compare data recorded among the three groups，determine whether there is a significant difference by statistical analysis.During the1-4weeks，As a control group, dental plaque of Group A are shiftedregularly，the implants are health with low clinical indices.Inflammation in Group Band Group C developed seriously with high clinical indices. PISF rise rapidly in week2, there are significant difference between Group A and the other two groups.The otherclinical indices appear significant difference in week3（P<0.01）.During the5-8weeks,without periodontal treatment, inflammation in Group Bdeveloped seriously with high clinical indicators.In the eighth week,the peri-implant pocket depth raised up to4-5mm，the top of the implants have been grewinto by soft tissue，removing the soft tissue, we can see2-3threads exposed. Afterperiodontal treatment, clinical indicators of Group C decreased,inflammatory symptoms disappear rapidly. In the fifth week, there was no significantdifference between Group A and Group C,but it appear significant difference betweenGroup B and Group C.2. Radiographc examination resultsX-ray at eighth week: bone tissue and abutment of implant contact closelyin Group A,and there appear a well bone contact.In Group B, compare with the X-rayof the fourth week,there became a larger”V”shape bone resorption,bonetissue absorption aggravate seriously, alveolar ridge reduced obviously.After periodontal treatment in Group C,alveolar ridge height increase,and appear awell bone contact similar to Group A.3. Histological observation under optical microscopeImplant thread can not been seen in slices of Group A，the top of implant was filledwith bone tissue. Between the implant and the alveolar ridge in Group B,there grewinto blue soft tissue,but no normal bone tissue,May be it was inflammatory softtissue,there was no well bone contact between the bone and the implant.The slices ofGroup C are similar to Group A, bone tissue around the abutment of implant grew well,appear a well bone contact after periodontal treatment,and activate the process ofregeneration of bone tissue destructed. But it can not rule out the possibility that theinflammation only limited to the soft tissue aroud implants,without bone resorption.ConclusionsThe experimental peri-implantitis animal model in beagle dogs are significantanimal models,it can induce peri-implantitis of the immediate implants naturallysimilar to human periodontitis.Inflammatory symptoms can disappear rapidly with lower clinical indicators after periodontal treatment.The result of experiment canprovide some help to clinic research on Immediate implants for periodontitis.